Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full behavioral burden, and it does disclose the underlying mechanism — it downloads a public CSV and searches within it — which implies network latency and no authentication requirement. It does not disclose what happens when the CNPJ is absent, when the download fails, or whether the CSV is cached, so the disclosure is partial.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences with the purpose front-loaded and the mechanism as supporting detail; nothing is wasted and nothing is buried.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a one-parameter lookup with an output schema defined, the description covers purpose and mechanism adequately; the remaining gaps (CNPJ format, not-found behavior) are modest but real for a tool whose only input is a loosely typed string.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

There is a single parameter with 0% schema description coverage, so the description must compensate; it does identify CNPJ as the lookup key but never specifies format (digits only vs. formatted with punctuation), which is the most likely source of invocation error for a Brazilian company registry.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description pairs a specific verb ('verifica se ... è sanzionata') with a specific resource (CEIS sanction list) and the key identifier (CNPJ), so the agent knows exactly what the tool answers. It does not, however, differentiate itself from siblings like buscar_empresa_por_cnpj, which an agent could plausibly confuse with a sanctions lookup.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no statement of when to use this tool versus buscar_empresa_por_cnpj, nor any prerequisite, exclusion, or caution. Usage is only inferable from the purpose sentence itself.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.